Communication apparatus, communication method, and program for exchanging data with a target

ABSTRACT

A communication device includes a first processing unit that detects a target and receives a first command for activating an interface upon a detection of the target. The communication device also includes a second processing unit that exchanges data with the target through the first processing unit. Further, the communication device includes an interface between the first processing unit and the second processing unit. The first processing unit selects a predetermined interface level from among a plurality of interface levels based on the first command and exchanges data with the second processing unit based on the predetermined interface level.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-264716 filed in theJapan Patent Office on Nov. 29, 2010, the entire content of which ishereby incorporated by reference.

FIELD

The present disclosure relates to a communication apparatus, acommunication method, and a program, and particularly to a communicationapparatus, a communication method and a program by each of which it ispossible to provide an interface which can be compatible with a case inwhich a plurality of types of targets and protocols are detected.

BACKGROUND

A near field communication system for performing wireless communicationat close range in a non-contact manner with the use of an IC (IntegratedCircuit) card is in widespread use. For example, the usage thereof as anelectronic travel ticket and electronic money is well known. Inaddition, recently, a mobile phone with a function as an electronictravel ticket and electronic money by non-contact wireless communicationhas been becoming widespread.

The near field wireless communication system has rapidly becomewidespread worldwide and recognized as an international standard.Examples of the international standard include ISO/IEC 14443 as thestandard of a proximity type IC card system, ISO/IEC 18092 as thestandard of NFCIP (Near Field Communication Interface and Protocol)-1,and the like.

In the near field wireless communication based on ISO/IEC 18092, thereare an active communication mode and a passive communication mode. Theactive communication mode is a communication mode in which datatransmission is performed by outputting electromagnetic waves from eachof a plurality of communication apparatuses exchanging data andmodulating a respective electromagnetic wave. In the passivecommunication mode, data transmission is performed by outputting anelectromagnetic wave from one (initiator) of the plurality ofcommunication apparatuses and modulating the electromagnetic wave. Theother communication apparatuses (targets) of the plurality ofcommunication apparatuses send data by performing load modulation on theelectromagnetic wave output from the initiator.

In the passive communication mode of ISO/IEC 18092 (hereinafter,referred to as type F), data encoding by Manchester coding is performedfor the data transmission between a reader writer and an IC card. Inaddition, 212 kbps and 424 kbps (kilobits per second) are employed asdata communication rates in the type F. The FeliCa (registeredtrademark) scheme by the applicant, Sony Corporation, corresponds to thetype F.

In addition, there are various communication schemes, for example,called type A and type B in the IC card system based on ISO/IEC 14443.

The type A is employed as the MIFARE (registered trademark) byKoninklijke Philips Electronics N.V. In the type A, the data encoding byMiller coding is performed for the data transmission from the readerwriter to the IC card while the data encoding by Manchester coding isperformed for the data transmission from the IC card to the readerwriter. In addition, 106 to 847 kbps (kilobit per second) is employed asthe data communication rate in the type A.

In the type B, the data encoding by NRZ encoding is performed for thedata transmission from the reader writer to the IC card while the dataencoding by NRZ-L is performed for the data transmission from the ICcard to the reader writer. In addition, 106 kbps is employed as the datacommunication rate in the type B.

The communication apparatus for the near field wireless communicationbased on ISO/IEC 18092 or ISO/IEC 14443 is referred to as an NFC deviceherein below. There are definitions of the protocol and the command tobe exchanged between a CLF (Contactless Front end) and an AP(Application Processor) while the NFC device is functionally dividedinto the CLF and the AP (see JP-T-2009-515250). The CLF mainly performstransceiving of the RF data with a target (a PICC (IC card) of ISO/IEC14443 or target of ISO/IEC 18092) while the AP mainly executes anapplication and performs overall control of the NFC device.

SUMMARY

However, JP-T-2009-515250 assumes only a case in which one kind oftarget and protocol are detected from among the type A and the type B ofISO/IEC 14443 and the type F of ISO/IEC 18092. In other words,JP-B-2009-515250 discloses an interface including the CLF and the AP onthe assumption that only one kind of target and protocol is detected.For this reason, the interface is not for the case in which a pluralityof kinds of targets and protocols are detected, and an interfaceincluding the CLF and the AP which can be compatible with a plurality ofkinds of targets and the protocols is desired.

Thus, it is desirable to provide an interface which can be compatiblewith a case in which a plurality of kinds of targets and protocols aredetected.

In one example, a communication device includes a first processing unitconfigured to detect a target and to receive a first command foractivating an interface upon a detection of the target. Thecommunication device also includes a second processing unit configuredto exchange data with the target through the first processing unit.Further, the communication device includes an interface between thefirst processing unit and the second processing unit. The firstprocessing unit is further configured to select a predeterminedinterface level from among a plurality of interface levels based on thefirst command and to exchange data with the second processing unit basedon the predetermined interface level.

The predetermined interface level can be selected based on an RFprotocol used in a communication between the target and the firstprocessing unit.

The first processing unit can be further configured to transmit a secondcommand and to receive a third command in response to the secondcommand, the third command indicating the RF protocol.

The first processing unit can be further configured to receive from thesecond processing unit a fourth command, the fourth command associatingthe RF protocol with the predetermined interface level.

The first processing unit can be further configured to send a fifthcommand based on the first command, the fifth command indicating thepredetermined interface level.

The first processing unit can be further configured to start and executean application based on the predetermined interface level, theapplication exchanging data between the second processing unit and thetarget using the RF protocol.

In another example, the first processing unit can be further configuredto receive a second command, to send a third command in response to thesecond command, and to receive the first command based on the thirdcommand.

In such an example, the first processing unit can be further configuredto receive from the second processing unit a fourth command, the fourthcommand associating the RF protocol with the predetermined interfacelevel.

Further to that example, the first processing unit can be furtherconfigured to send a fifth command in response to the first command, thefifth command indicating the predetermined interface level.

In a further example, the predetermined interface level can be selectedbased on an RF technology used in a communication between the target andthe first processing unit.

According to such an example, the first processing-unit can be furtherconfigured to transmit a second command and to receive a third commandin response to the second command, the third command indicating the RFtechnology.

Additionally in that example, the first processing unit can be furtherconfigured to transmit a fourth command to the second processing unit,the fourth command indicating the RF technology.

Further to such an example, the first processing unit can be configuredto start and execute an application based on the predetermined interfacelevel, the application exchanging data between the first processing unitand the target using the RF technology.

Further to that example, the first processing unit can be configured toreceive a second command, to send a third command in response to thesecond command, and to receive the first command based on the thirdcommand.

Additionally, in such an example, the first processing unit can befurther configured to send a fourth command in response to the firstcommand, the fourth command indicating the predetermined interfacelevel.

In another example, the first processing unit can be further configuredto receive a second command representing a version of the secondprocessing unit, and the first processing unit can be further configuredto transmit a third command in response to the second command, thesecond command representing a version of the first processing unit. Whenthe version of the second processing unit is equivalent or higher thanthe version of the first processing unit, the interface exchangesmessages.

In such an example, the third command also represents the predeterminedinterface level, and, when the version of the second processing unit isequivalent or higher than the version of the first processing unit, thesecond processing unit transmits the command, the command indicating atleast one of a poll mode and a listen mode, an RF protocol, and aninterface level.

In another example, a communication method includes detecting a target,and receiving, at a first processing unit, a first message foractivating an interface upon the detecting. The communication methodalso includes exchanging data between a second processing unit and thetarget through the first processing unit. The communication methodfurther includes selecting, with the first processing unit, apredetermined interface level from among a plurality of interface levelsbased on the first message. In addition, the communication methodincludes exchanging data between the first processing unit and thesecond processing unit based on the predetermined interface level.

According to another example, a non-transitory, computer-readablestorage medium is encoded with computer executable instructions. Theinstructions, when executed by a communication device, cause thecommunication device to perform a method including detecting a targetand receiving, at a first processing unit, a first message foractivating an interface upon the detecting. The method also includesexchanging data between a second processing unit and the target throughthe first processing unit. Further, the method includes selecting, withthe first processing unit, a predetermined interface level from among aplurality of interface levels based on the first message. In addition,the method includes exchanging data between the first processing unitand the second processing unit based on the predetermined interfacelevel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration example of anembodiment of a communication system to which the present disclosure isapplied;

FIG. 2 is a diagram showing an interface level settable for each RFprotocol;

FIG. 3 is a diagram showing a difference in processing in accordancewith an interface level in the case of a communication layer for P2Pcommunication between NFC devices;

FIG. 4 is a diagram illustrating a detailed format of each message;

FIG. 5 is a diagram illustrating a detailed format of each message;

FIG. 6 is a diagram illustrating a detailed format of each message;

FIG. 7 is a diagram illustrating a detailed format of each message;

FIG. 8 is a diagram illustrating a detailed format of each message;

FIG. 9 is a diagram illustrating a detailed format of each message;

FIG. 10 is a diagram showing a list of messages;

FIG. 11 is a flowchart illustrating a sequence outline;

FIG. 12 is a diagram illustrating a detailed sequence example in thecase of a Poll Mode;

FIG. 13 is a flowchart illustrating a detailed sequence example in thecase of a Poll Mode;

FIG. 14 is a flowchart illustrating a detailed sequence example in thecase of a Listen Mode; and

FIG. 15 is a flowchart illustrating a detailed sequence example in thecase of a Listen Mode.

DETAILED DESCRIPTION Configuration Example of Communication System towhich Present Disclosure is Applied

FIG. 1 shows a configuration example of a communication system accordingto an embodiment to which the present disclosure is applied.

The communication system in FIG. 1 includes an NFC device 1 and NFCdevices 11-1 to 11-3.

The NFC device 1 and the NFC devices 11-1 to 11-3 are communicationapparatuses for near field wireless communication based on one or bothof ISO/IEC 18092 and ISO/IEC 14443. The NFC device 1 and the NFC devices11-1 to 11-3 can be operated as either of a polling device and alistening device.

The polling device forms a so-called RF (Radio Frequency) field(magnetic field) by generating an electromagnetic wave, sends a pollingcommand to detect a listening device as a target, and waits for theresponse from the listening device. In other words, the polling deviceperforms an operation of a PCD (Proximity Coupling Device) of ISO/IEC14443 or an operation of an initiator in the passive mode of ISO/IEC18092.

The listening device receives a polling command which is sent from thepolling device by forming the RF field and then responds with a pollingresponse. In other words, the listening device performs the operation ofPICC of ISO/IEC 14443 or the operation of the target of ISO/IEC 18092.

Accordingly, the NFC device 1 and the NFC devices 11-1 to 11-3 may havethe same hardware configurations, respectively.

The NFC devices 11-1 to 11-3 are respectively referred to as targets11-1 to 11-3 hereinbelow to simplify the difference between the NFCdevice 1 and the NFC devices 11-1 to 11-3. In addition, when it is notparticularly necessary to distinguish the targets 11-1 to 11-3, thetargets 11-1 to 11-3 are simply referred to as a target 11 (or an NFCdevice 11).

The NFC device 1 includes one AP (Application Processor) 21, one CLF(Contactless Front end) 22, and 0 or more SEs (Secure Element) 23. Since0 or more SEs 23 are provided, the number thereof may be 0 (the SE 23may be omitted).

The AP 21 performs overall control of the NFC device 1, generates acommand (CMD) for controlling the CLF 22, and analyzes an executionresult with respect to the command. The AP is an example of a processingmeans. The AP 21 exchanges a message with the CLF 22 in accordance withthe HCI (Host Controller Interface). In addition, the AP 21 executes anapplication for data exchange with the target 11. Examples of theapplication include an application which performs data exchangeprocessing for name cards and an address book in the P2P (Peer-to-Peer)communication, electronic money payment processing, and the like betweena reader writer and an IC card. In addition, the AP 21 stores thereinthree applications App (H), App (M), and App (L) with different levelsas the applications for data exchange in accordance with the level ofthe interface of the CLF 22 (interface level).

Thus, the CLF 22 includes a memory. The memory can also be external tothe CLF 22. The memory can be a ROM, a RAM, a magnetic disk, an opticaldisk, or any other memory.

Further, the memory is an example of a storing means. When the APexecutes a program to perform a method according to some embodiments,the memory is an example of a non-transitory storage medium.

The CLF 22 is an interface which is disposed between the AP 21 and thetarget 11 to mediate therebetween and controls the path such that the AP21 and the SE 23 can exchange data with the target 11. The CLF is anexample of a processing means. The CLF 22 has a plurality of interfacelevels as the interface level for mediating the AP 21 and the target 11.In this embodiment, the CLF 22 is assumed to have three stages ofinterface levels including a low level, a middle level, and a highlevel. The CLF 22 is instructed by the HCI and exchanges messages withthe AP 21 and performs transceiving of RF data through an antenna 24based on a command (CMD) from the AP 21.

The HCI is a logical interface between the AP 21 and the CLF 22, and acommand (CMD) and a notification (NTF) in a predetermined format whichwill be described later are defined in the HCI.

The SE 23 performs processing and retaining of secure data from amongthe processing which are necessary for the data exchange between the NFCdevice 1 and the target 11. In the example of FIG. 1, three SEs 23-1 to23-3 are provided in the NFC device 1. The SEs 23-1 and 23-2 areconnected to the CLF 22 to perform retaining and processing of securedata which is treated by the CLF 22 while the SE 23-3 is connected tothe AP 21 to perform retaining and processing of secure data which istreated by the AP 21. It is possible to provide a necessary number ofSEs 23 in the NFC device 1 or omit the SEs 23 if it is not necessary.

The antenna 24 constitutes a closed-loop coil and outputs anelectromagnetic wave (RF data) if the current flowing through the coilchanges. The antenna is an example of a transmitting means and/or areceiving means.

The NFC device 1 configured as described above supports one or more ofthe following three RF technologies.

(1) NFC-A . . . Type A communication scheme of ISO/IEC 14443

(2) NFC-B . . . Type B communication scheme of ISO/IEC 14443

(3) NFC-F . . . 212 kbps and 424 kbps communication schemes of ISO/IEC18092

The NFC-A is an abbreviated expression of Type A of ISO/IEC 14443, theNFC-B is an abbreviated expression of Type B of ISO/IEC 14443, and theNFC-F is an abbreviated expression of 212 kbps and 424 kbpscommunication schemes of ISO/IEC 18092, in this specification.

In addition, the NFC device 1 supports one or more of the following sixRF protocols.

(1) T1T . . . TYPE 1 TAG PLATFORM Protocol (based on Type NFC-A)

(2) T2T . . . TYPE 2 TAG PLATFORM Protocol (based on Type NFC-A)

(3) T3T . . . TYPE 3 TAG PLATFORM Protocol (based on Type NFC-F)

(4) ISO-DEP . . . ISO-DEP Protocol (ISO/IEC 14443-4 based on Type NFC-Aor NFC-B)

/TYPE 4 TAG PLATFORM Protocol (based on Type NFC-A or NFC-B)

(5) NFC-DEP . . . NFC-DEP Protocol (ISO/IEC 18092 transport protocolbased on NFC-A or NFC-F)

(6) Prop . . . Proprietary Definition Protocol (Proprietary Protocol)

The T1T is an abbreviated expression of TYPE 1 TAG PLATFORM Protocol(based on NFC-A), and the T2T is an abbreviated expression of TYPE 2 TAGPLATFORM Protocol (based on NFC-A), in this specification. The same istrue for the T3T, the ISO-DEP, the NFC-DEP, and the Prop.

[Concerning Interface Level]

When the NFC device 1 exchanges data with the target 11, the NFC device1 can allot processing to the AP 21 and the CLF 22. In other words, itis possible to cause the intermediate-CLF 22 to perform processing whichis necessary for the data exchange with the target 11 instead of the AP21. At this time, to which level the CLF 22 performs the processingnecessary for the data exchange instead is determined based on theinterface level designated (notified) from the AP 21 to the CLF 22.

From among the three stages of interface levels including a low level, amiddle level, and a high level of the CLF 22, the high level is a levelat which the amount of processing allotted to the CLF 22 as an interfaceis the largest, and the low level is a level at which the amount ofprocessing allotted to the CLF 22 as an interface is the smallest. It isnecessary to set the interface level for each RF protocol, and asettable interface level is set in advance depending on the RF protocolin the CLF 22.

FIG. 2 shows the interface level which can be set for the RF protocol bythe CLF 22.

Only a low interface level can be set for each of the RF protocols T1T,T2T, and T3T. In addition, the RF technology when the RF protocol is T1Tand T2T is NFC-A, and the RF technology when the RF protocol is T3T isNFC-F.

It is possible to set any of the interface levels from among the lowlevel, the middle level, and the high level for each of the RF protocolsISO-DEP and NFC-DEP. The RF technology when the RF protocol is ISO-DEPis NFC-A or NFC-B, and the RF technology when the RF protocol is NFC-DEPis NFC-A or NFC-F.

Only the low interface level can be set for the RF protocol Prop.

FIG. 3 shows a difference in processing depending on the interface levelin the case of a communication layer for the P2P communication betweenNFC devices.

At the low interface level, the CLF 22 has functions of Frame format,Anticollision, Bit coding, and Modulation/Load modulation based onISO/IEC 18092. At the middle interface level, the CLF 22 further hasfunctions up to a transport protocol based on ISO/IEC 18092. That is,the CLF 22 further has functions of Protocol activation/deactivation,Segmentation and reassembly, and Retransmission as well as the functionsat the low level. At the high interface level, the CLF 22 has functionsup to LLCP (NFC Forum Logical Link Control Protocol) which is a higherlayer protocol of transport protocol based on ISO/IEC 18092.

It is possible to set and mount the interface level of the CLF 22 foreach RF protocol from among the three stages in accordance with theapplication conditions, the costs of the IC chips, and the like whichare assumed by the CLF 22.

In initial processing, the CLF 22 notifies the AP 21 of the informationregarding up to which interface level the CLF 22 itself supports. The AP21 grasps the interface level supported by the CLF 22, selects anoptimal interface level from among the interface levels supported by theCLF 22 in accordance with the application conditions assumed by the AP21, and designates the interface level for the CLF 22. When the CLF 22supports all interface levels, the AP 21 can select an optimal interfacelevel in accordance with the processing supported by the application.For example, when it is desired that the AP 21 executes an applicationwith less processing, the AP 21 may select and designate the highinterface level for the CLF 22.

[Message Format]

Next, detailed description will be made of a message defined as an HCIwith reference to FIGS. 4 to 9.

There are three kinds of messages including a CMD (command) from the AP21 to the CLF 22, an RSP (response) from the CLF 22 to the AP 21 for thecommand, and an NTF (notification) from the CLF 22 to the AP 21.

FIG. 4 shows formats for an initialization command “INIT_COM” and aninitialization response “INIT_RES”.

The initialization command “INIT_COM” is a message for initialization ofthe HCI and the ability exchange between the CLF 22 and the AP 21. Theinitialization command “INIT_COM” includes “Version” representing theHCI version (version number) of the AP 21 and “HCI Features”representing the ability of the AP 21 as parameters. The informationregarding the communication control functions supported by the AP 21such as information regarding the presence of a flow control function, acard emulation function, an additional message creation function, andthe like is input in “HCI Features”.

The initialization response “INIT_RES” is a message for responding tothe initialization command. The initialization response “INIT_RES”includes “Status” representing the response result for theinitialization command “INIT_COM”, “Version” representing the HCIversion of the CLF 22, “HCI Features” representing the ability of theCLF 22, and “HCI Interfaces” representing the interface ability of theCLF 22 as parameters. The information regarding the communicationcontrol functions supported by the CLF 22 such as information regardingthe presence of a flow control function, a battery OFF mode function, arouting function with the use of an application identifier of cardemulation, and the like is input in “HCI Features”. The interface levelfor each RF protocol supported by the CLF 22 is input in “HCIInterfaces”.

The AP 21 and the CLF 22 mutually check the versions thereof by theinitialization command “INIT_COM” and the initialization response“INIT_RES”, and it is possible to exchange messages while beinginstructed by the HCI if the version of the AP 21 is equivalent orhigher than the version of the CLF 22. On the other hand, if the versionof the AP 21 is lower than the version of the CLF 22, the AP 21 performserror processing such as an output of an error message.

FIG. 5 shows formats for the interface level setting command“SET_INTERFACE_LEVEL_COM” and the interface level setting response“SET_INTERFACE_LEVEL_RES”.

The interface level setting command “SET_INTERFACE_LEVEL_COM” is amessage for associating the RF protocol and the interface level. Theinterface level setting command “SET_INTERFACE_LEVEL_COM” includes thenumber [n] of interface level setting data items and n interface levelsetting data items.

The interface level setting data for one RF protocol includes “Mode”representing the mode (Poll mode/Listen Mode) of the target 11,“Protocol” representing the used RF protocol, and “Interface level”representing the used interface level. That is, it is possible to setthe interface level (“Interface level”) for each of the Poll Mode andthe Listen Mode for one RF protocol (“Protocol”). For example, settingcan be made such that the middle interface level is set for the case ofthe Poll Mode when the RF protocol is ISO-DEP and the high interfacelevel is set for the case of the Listen Mode when the RF protocol isISO-DEP. Accordingly, the number n of the interface level setting dataitems becomes twice as large as the number of the RF protocols at amaximum.

The interface level setting response “SET_INTERFACE_LEVEL_RES” is amessage for responding to the interface level setting command. Theinterface level setting response “SET_INTERFACE_LEVEL_RES” includesOK=1, or NG=0, which represents the response result, as a parameter.

FIG. 6 shows formats for the discovery start command“DISCOVER_START_COM”, the discovery start response “DISCOVER_START_RES”,the discovery stop command “DISCOVER_STOP_COM” and the discovery stopresponse “DISCOVER_STOP_RES”.

The discovery start command “DISCOVER_START_COM” is a message forrequesting the start of the detection of the target 11. The parameter ofthe discovery start command “DISCOVER_START_COM” includes “DiscoveryTypes” representing the RF technologies as detection targets, the numberof which corresponds to the number of the RF technologies which aredesired to be detected.

The discovery start response “DISCOVER_START_RES” is a message forresponding to the discovery start command. The discovery start response“DISCOVER_START_RES” includes OK=1 or NG=0, which represents theresponse result, as a parameter.

The discovery stop command “DISCOVER_STOP_COM” is a message forrequesting the detection of the target 11 to be stopped. The discoverystop command “DISCOVER_STOP_COM” does not include any parameters.

The discovery stop response “DISCOVER_STOP_RES” is a message forresponding to the discovery stop command. The discovery stop response“DISCOVER_STOP_RES” includes OK=1 or NG=0, which represents the responseresult, as a parameter.

FIG. 7 shows formats for the discovery selection command“DISCOVER_SELECT_COM”, the discovery selection response“DISCOVER_SELECT_RES”, the deactivation command “DEACT_COM”, and thedeactivation response “DEACT_RES”.

The discovery selection command “DISCOVER_SELECT_COM” is a message forselecting the RF technology (target 11) and the RF protocol. A selectedRF technology (target 11) is input in the parameter “Target ID”, and aselected RF protocol is input to the parameter “Target SAP” of thediscovery selection command “DISCOVER_SELECT_COM”.

The discovery selection response “DISCOVER_SELECTRES” is a message forresponding to the discovery selection command. The discovery selectionresponse “DISCOVER_SELECT_RES” includes OK=1 or NG=0, which representsthe response result, as a parameter.

The deactivation command “DEALT_COM” is a message for requesting thecompletion of the data exchange with the target 11. The deactivationcommand “DEACT_COM” includes “Target ID” corresponding to the RFtechnology, “Target SAP” corresponding to the RF protocol, and“Deactivation Type” which is the command to be sent to the target, asparameters.

The deactivation response “DEACT_RES” is a message for responding to thedeactivation command “DEACT_COM”. The deactivation response “DEACT_RES”includes OK=1 or NG=0, which represents the response result, as aparameter.

FIG. 8 shows formats for the discovery notification “DISCOVER_NTF”, theactivation notification “ACT_NTF”, and the deactivation notification“DEACT_NTF”.

The discovery notification “DISCOVER_NTF” is a message for thenotification of the target, and the RF technology and the RF protocolthereof. There are a plurality of combinations of the target, the RFtechnology, and the RF protocol in some cases in the same manner as inthe aforementioned discovery selection command “DISCOVER_SELECT_COM”.

The discovery notification “DISCOVER_NTF” includes “Target ID” which isthe number allotted by the CLF 22 to the RF technology, “Target SAP”which is the number allotted by the CLF 22 to the RF protocol,“Discovery Type” representing the detected RF technology, “RF Protocol”representing the RF protocol of the target 11, the “Technology SpecificParameters” representing the RF technology specific parameter, and“More” representing the presence of the next discovery notification“DISCOVER_NTF”, as parameters.

The activation notification “ACT_NTF” is a message for the notificationof the activation (activating, starting) of a specific interface level(activation, start). The activation notification “ACT_NTF” includes“Activation Parameters” representing the activation parameters and“Interface Type” representing the activated interface level as well asthe aforementioned “Target ID”, “Target SAP”, “Discovery Type”, and “RFprotocol”, as parameters.

The deactivation notification “DEACT_NTF” is a message for thenotification of the deactivation (deactivating) of a specific interfacelevel. The deactivation notification “DEACT_NTF” includes “DeactivationParameters” representing the deactivation parameters as well as theaforementioned “Target ID” and “Target SAP”, as parameters.

FIG. 9 shows a list of messages described with reference to FIGS. 4 to8.

[Sequence Outline]

Next, description will be made of the outline of the sequence performedbetween the AP 21 and the CLF 22 when the AP 21 exchanges data with thetarget 11 with reference to FIG. 10.

The sequence performed between the AP 21 and the CLF 22 when the AP 21exchanges data with the target 11 roughly includes the following fivesteps.

(1) Initialization processing for setting interface level for RFprotocol

(2) Discovery processing for target 11

(3) Activation processing for interface

(4) Data exchange processing

(5) Deactivation processing for interface

When the AP 21 exchanges data with a plurality of targets 11, the stepsfrom (3) to (5) are sequentially executed for each of the plurality oftarget 11.

(1) Initialization Processing for Setting Interface Level for RFProtocol

In the initialization processing, the AP 21 designates (notifies of) theinterface level of the CLF 22 by sending the interface level settingcommand “SET_INTERFACE_LEVEL_COM” after checking the interface abilityof the CLF 22. The initialization processing corresponds to theprocessing in Step S11 of the AP 21 and the processing in Step S21 ofthe CLF 22 in FIG. 10.

(2) Discovery Processing for Target 11

The discovery processing is processing for detecting the target 11. Ifthe AP 21 sends the discovery start command “DISCOVER_START_COM” forrequesting the start of the detection of the target 11 to the CLF 22 inStep S12, the CLF 22 starts the processing of detecting the target 11 inStep S22.

In the detection of the target 11, the CLF 22 alternately repeats thePoll Mode and the Listen Mode. That is, the CLF 22 repeats processing ofsetting the polling command and waiting for the response from thecounterpart (Poll Mode) and processing of waiting for the pollingcommand from the counterpart (Listen Mode) thereafter.

In the Poll Mode, if the CLF 22 receives a response for the sent pollingcommand, the communication link with the target 11 is regarded to havebeen established, and the mode at that time (Poll Mode) is maintained.In the Poll Mode, the CLF 22 can act as a PCD or an Initiator and send acommand.

On the other hand, in the Listen Mode, if the CLF 22 sends a response tothe polling command from the counterpart, the communication link withthe target 11 is regarded to have been established, and the mode at thattime (Listen Mode) is maintained. In the Listen Mode, the CLF 22 can actas a PICC or a Target and respond to the received command (send theresponse).

The CLF 22 notifies the AP 21 of the detected target 11 by the discoverynotification “DISCOVER_NTF” in Step S23. When a plurality of targets 11are detected, the CLF 22 sends the discovery notification “DISCOVER_NTF”for each of all detected targets 11.

(3) Activation Processing for Interface

The AP 21 receives the discovery notification “DISCOVER_NTF”, thenselects one predetermined target 11 from among the received targets, andsends the discovery selection command “DISCOVER_SELECT_COM” to the CLF22 in Step S13.

The CLF 22 receives the discovery selection command“DISCOVER_SELECT_COM” and activates the interface of the one selectedtarget 11 based on the discovery selection command “DISCOVER_SELECT_COM”in Step S24. Then, the CLF 22 notifies the AP 21 of the fact that theinterface of the target 11 selected by the discovery selection command“DISCOVER_SELECT_COM” has been activated, by the activation notification“ACT_NTF”.

In addition, this processing is processing in the case of the Poll Mode,and different processing is performed in the case of the Listen Modesince the AP 21 does not select the target 11. That is, the CLF 22responds with a plurality of RF technologies in the Listen Mode when theCLF 22 retains a state machine for the plurality of RF technologies. TheCLF 22 responds with the RF technology detected first when the CLF 22retains a state machine for one RF technology. The CLF 22 activates theinterface of the responding target 11 and notifies the AP 21 of the factby the activation notification “ACT_NTF”. Since the target 11 sends acommand in the Listen Mode, the CLF 22 performs processing in accordancewith the received command.

(4) Data Exchange Processing

The AP 21 receives the activation notification “ACT_NTF” from the CLF 22and then activates the application in Step S14. At this time, the AP 21selects one of the applications App (H), App (M), and App (L) inaccordance with the interface level of the CLF 22.

The AP 21 exchanges data with the target 11 through the CLF 22 by theactivated application in Step S15. The CLF 22 exchanges data between theAP 21 and the target 11 in Step S25.

(5) Deactivation Processing for Interface

In the Poll Mode, the application activated in the AP 21 sends thedeactivation command “DEACT_COM” to the CLF 22 at the time of thecompletion of the application. The CLF 22 receives the deactivationcommand “DEACT_COM”, deactivates the interface of the communicatingtarget 11, and disconnects the communication link with the target 11 inStep S26.

On the other hand, the CLF 22 sends the deactivation notification“DEACT_NTF” to the AP 21 after the disconnection of the communicationlink with the communicating target 11 in the Listen Mode. The AP 21completes the application when the deactivation notification “DEACT_NTF”is received in Step S16.

The rough sequence flow has been described above for the example inwhich communication is performed by one target 11.

[Detailed Example of Sequence (in the Case of Poll Mode)]

Hereinafter, detailed description will be made of the sequence performedbetween the AP 21 and the CLF 22 when the AP 21 exchanges data with aplurality of targets 11 with reference to FIGS. 11 to 13.

FIG. 11 shows the RF technology and the RF protocol supported by each ofthe targets 11-1 to 11-3.

The target 11-1 supports NFC-A as the RF technology and two RF protocolsincluding ISO-DEP and NFC-DEP. The target 11-2 supports NFC-B as the RFtechnology and ISO-DEP as the RF protocol. The target 11-3 supports theNFC-F as the RF technology and T3T as the RF protocol.

In FIG. 11, “Target ID” and “Target SAP” shown in the right side of thesection for the RF protocol represent identifiers allotted to thedetected target 11 by the CLF 22 in a series of sequence shown in FIGS.12 and 13.

[Sequence Example for Poll Mode]

FIGS. 12 and 13 are flowcharts showing a sequence in which the NFCdevice 1 (CLF 22) is operated in the Poll Mode to communicate with threetargets 11-1 to 11-3 with different RF technologies.

First, the AP 21 sends an initialization command INIT_COM in Step S41,and the CLF 22 sends an initialization response INIT_RES as a responseto the AP 21 in Step S42. The initialization response INIT_RES includesan interface level for each R-F protocol supported by the CLF 22 asdescribed above.

In Step S43, the AP 21 sends an interface level setting commandSET_INTERFACE_LEVEL_COM for associating the RF protocol and theinterface level to the CLF 22 based on the interface level for each RFprotocol supported by the CLF 22. In Step S43, SET_INTERFACE_LEVEL_COM(5, Poll, ISO-DEP Protocol, Mid I/F Level, Poll, NFC-DEP Protocol, HighI/F Level, Poll, T1T Protocol, Low I/F Level, Poll, T2T Protocol, LowI/F Level, Poll, T3T Protocol, Low I/F Level) is sent. With such acommand, the middle interface level is set when the RF protocol isISO-DEP, the high interface level is set for NFC-DEP, and the lowinterface level is set for T1T, T2T, and T3T in the CLF 22 in the PollMode.

Although setting is made for the RF protocols T1T, T2T, and T3T in thisexample, the levels of the RF protocols T1T, T2T, and T3T may be fixedto the low level, and the sending of the command and the setting may beomitted since only the low interface level can be set for the RFprotocols T1T, T2T, and T3T.

Since the sequence of FIG. 12 describes an example in which the NFCdevice 1 (CLF 22) is operated in the Poll Mode, the designation of eachinterface level in the Listen Mode is omitted in the interface levelsetting command SET_INTERFACE_LEVEL_(—) COM in Step S43.

The CLF 22 sends an interface level setting responseSET_INTERFACE_LEVEL_RES-which represents that the interface levelsetting command SET_INTERFACE_LEVEL_COM from the AP 21 has beenunderstood in Step S44.

Then, the AP 21 designates NFC-A, NFC-B, and NFC-F as the RFtechnologies of the detection targets and sends a discovery startcommand DISCOVER_START_COM to the CLF 22 in Step S45. The CLF 22 sends adiscovery start response DISCOVER_START_RES representing that thediscovery start command DISCOVER_START_COM has been understood to the AP21 in Step S46.

Then, the CLF 22 sends a command for detecting the targets 11 for NFC-A,NFC-B, and NFC-F designated as the RF technologies of the detectiontargets. Specifically, the AP 21 sends a command SENS_REQ for NFC-A inStep S47 and receives a response SENS_RES for the command SENS_REQ whichis sent from the target 11-1 in the RF field in Step S48. The RFprotocol of the target 11-1 is not yet known at the time of receivingthe response SENS_RES.

In addition, the AP 21 sends a command SENSB_REQ for NFC-B in Step S49and receives a response SENSB_RES for the command SENSB_REQ which issent from the target 11-2 in the RF field in Step S50. The fact that theRF protocol of the target 11-2 is ISO-DEP is known by receiving theresponse SENSB_RES.

Moreover, the AP 21 sends a command SENSF_REQ for NFC-F in Step S51 andreceives a response SENSF_RES for the command SENSF_REQ which is sentfrom the target 11-3 in the RF field in Step S52. The fact that the RFprotocol of the target 11-3 is T3T is known by receiving the responseSENSF_RES.

Although the CLF 22 alternately repeats the Poll Mode and the ListenMode if no target 11 is detected, the operation in the Listen Mode isnot performed since the targets 11-1 to 11-3 are detected in the PollMode.

The CLF 22 sends three discovery notifications DISCOVER_NTF for thenotification of the detected targets 11-1 to 11-3 to the AP 21 in StepsS53 to S55. Specifically, the CLF 22 allots “TID1” as the Target ID and“TSAP1” as the Target SAP for the detected target 11-1 of NFC-A andsends a discovery notification DISCOVER_NTF to the AP 21 in Step S53.

The CLF 22 allots “TID2” as the Target ID and “TSAP2” as the Target SAPfor the detected target 11-2 of NFC-B and sends a discovery notificationDISCOVER_NTF to the AP 21 in Step S54. The CLF 22 allots “TID3” as theTarget ID and “TSAP3” as the Target SAP for the detected target 11-3 ofNFC-F and sends a discovery notification DISCOVER_NTF to the AP 21 inStep S55.

Here, the last parameters “More” of the discovery notificationsDISCOVER_NTF sent in Steps S53 and S54 are “1” since the discoverynotification DISCOVER_NTF will be sent again. On the other hand, thelast parameter “More” of the discovery notification DISCOVERY_NTF sentin Step S55 is “0” since no discovery notification DISCOVER_NTF will besent again.

In the following sequence, the target 11 is specified by the Target IDand the Target SAP allotted by the CLF 22, and messages are exchangedbetween the AP 21 and the CLF 22.

The AP 21 selects communication with the target 11-2 from among thedetected targets 11-1 to 11-3 and sends a discovery selection commandDISCOVER_SELECT_COM with parameters of TID2 for “Target ID” and TSAP2for “Target SAP” in Step S56.

The CLF 22 receives the discovery selection command DISCOVER_SELECT_COMand sends a discovery selection response DISCOVER_SELECT_RESrepresenting that the command has been understood to the AP 21 in StepS57.

The middle interface level is designated by the aforementioned interfacelevel setting command SET_INTERFACE_LEVEL_COM for the RF protocol ofISO-DEP represented by “Target SAP”=TSAP2 included in the discoveryselection command DISCOVER_SELECT_COM. The protocol activation is theprocessing performed by the CLF 22 in the middle interface level asdescribed above with reference to FIG. 3.

Thus, the CLF 22 performs the protocol activation in Step S58. That is,the CLF 22 informs of its own attributes (specifications) and sends anATTRIB command for requesting the attributes of the target 11-2 to thetarget 11-2. The CLF 22 receives a response ATTA from the target 11-2 asa response for the ATTRIB command in Step S59.

If the response ATTA is received, the CLF 22 sends an activationnotification ACT_NTF representing the fact that the activation of theinterface in the middle interface level has been completed to the AP 21in Step S60. The parameters of the activation notification ACT_NTFinclude a received response “ATTA” as “Activation Parameter” and “MidI/F Level activated” representing the activated interface level as“Interface Type”.

After the completion of the interface activation, the application App(M) corresponding to the middle interface level in the AP 21 is startedto exchange data between the AP 21 and the target 11-2 (TID2) with theuse of the RF protocol ISO-DEP (TSAP2) in Step S61.

When predetermined data exchange is performed, and the application App(M) is completed, the AP 21 sends a deactivation command DEACT_COM tothe CLF 22 in Step S62. The parameter “Deactivation Type” of thedeactivation command DEACT_COM includes a command “DESELECT” to be sentto the target 11-2.

The CLF 22 sends a deactivation response DEACT_RES representing the factthat the deactivation command DEACT_COM has been understood to the AP 21in Step S63.

Then, the CLF 22 sends a DESELECT command to the target 11-2 based onthe parameter “Deactivation Type” included in the deactivation commandDEACT_COM in Step S64. The CLF 22 receives the response DESELECT fromthe target 11-2 and deactivates the interface in Step S65. Theparameters relating to the target 11-2 (TID2) and ISO-DEP (TSAP2) arereleased by the deactivation of the interface.

From Step S66 in FIG. 13, the target 11-1 (TID1) is selected as acommunication counterpart, and communication is performed between the AP21 and the target 11-1 (TID1).

That is, the AP 21 sends a discovery selection commandDISCOVER_SELECT_COM with parameters of TID1 as “Target ID” and TSAP1 as“Target SAP” to the CLF 22 in Step S66.

The CLF 22 receives the discovery selection command DISCOVER_SELECT_COMand sends a discovery selection response DISCOVER_SELECT_RESrepresenting that the command has been understood to the AP 21 in StepS67.

Then, the CLF 22 recognizes a predetermined PICC and performsanticollision processing for communication even if a plurality of PICCs(IC cards) exist between the CLF 22 and the target 11-1 corresponding tothe parameter TID1 and the TSAP1, in Step S68.

In Step S69, the CLF 22 receives a response SEL_RES (ISO-DEP|NFC-DEP)representing that ISO-DEP and NFC-DEP are supported as the RF protocolsfrom the target 11-1.

The CLF 22 allots “TSAP4” as the Target SAP for the RF protocol ISO-DEPand “TSAP5” as the Target SAP for the RF protocol NFC-DEP, and sendsdiscovery notifications DISCOVER_NTF to the AP 21 in Steps S70 and S71.That is, the CLF 22 sends a discovery notification DISCOVER_NTF (TID1,TSAP4, NFC-A, PROTOCOL_ISO_DEP, SEL_RES, More=1) to the AP 21 in StepS70 and sends a discovery notification DISCOVER_NTF (TID1, TSAP5, NFC-A,PROTOCOL_NFC_DEP, SEL_RES, More=0) to the AP 21 in Step S71.

The AP 21 selects NFC-DEP from among the two RF protocols and sends adiscovery selection command DISCOVER_SELECT_COM with parameters TID1 as“Target ID” and TSAP5 as “Target SAP” in Step S72.

In Step S73, the CLF 22 receives the discovery selection commandDISCOVER_SELECT_COM and sends a discovery selection responseDISCOVER_SELECT_RES representing that the command has been understood tothe AP 21.

The high interface level is designated for the RF protocol NFC-DEP inthe aforementioned interface level setting in Step S43. Thus, the CLF 22performs protocol activation (ATR_REQ command for requesting attributes)and LLCP activation in Step S74.

In Step S75, the CLF 22 receives the results of the response ATR_RES andthe LLCP activation as a response to the ATR_REQ command from the target11-1. Then, the CLF 22 sends an activation notification ACT_NTFrepresenting the fact that the interface activation in the high levelhas been completed to the AP 21 in Step S76. The parameters of theactivation notification ACT_NTF include received response “ATR_RES” as“Activation Parameter” and “High I/F Level activate” representing theactivated interface level as “Interface Type”.

After the completion of the interface activation, the application App(H) corresponding to the high interface level in the AP 21 is started toexchange data between the AP 21 and the target 11-1 (TID1) with the useof the RF protocol NFC-DEP (TSAP5) in Step S77.

When predetermined data exchange is performed, and the application App(H) is completed, the AP 21 sends a deactivation command DEACT_COM tothe CLF 22 in Step S78. The parameter “Deactivation Type” of thedeactivation command DEACT_COM includes a command “DSL_REQ” to be sentto the target 11-1.

The CLF 22 sends a deactivation response DEACT_RES representing the factthat the deactivation command DEACT_COM has been understood to the AP 21in Step S79.

Then, the CLF 22 sends a DSL_REQ command to the target 11-1 based on theparameter “Deactivation Type” included in the deactivation commandDEACT_COM in Step S80. The CLF 22 receives the response DSL_RES from thetarget 11-1 and deactivates the interface in Step S81. The parametersrelating to the target 11-1 (TID1) and NFC-DEP (TSAP5) are released bythe deactivation of the interface.

From Step S82, the target 11-3 (TID3) is selected as a communicationcounterpart, and communication is performed between the AP 21 and thetarget 11-3 (TID3).

Specifically, the AP 21 sends a discovery selection commandDISCOVER_SELECT_COM with parameters of TID3 (NFC-F) as “Target ID” andTSAP3 (T3T) as “Target SAP” to the CLF 22 in Step S82.

The CLF 22 receives the discovery selection command DISCOVER_SELECT_COMand sends a discovery selection response DISCOVER_SELECT_RESrepresenting that the command has been understood to the AP 21 in StepS83.

The low interface level is designated for the RF protocol T3T in theaforementioned interface level setting in Step S43. No protocolactivation is performed in the low interface level. Therefore, the CLF22 immediately sets “NULL” for the parameter of “Activation Parameters”and sends an activation notification ACT_NTF representing that theinterface activation in the low level has been completed to the AP 21 inStep S84.

After the completion of the interface activation, the application App(L) corresponding to the low interface level in the AP 21 is started toexchange data between the AP 21 and the target 11-3 (TID3) with the useof the RF protocol T3T (TSAP3) in Step S85.

When predetermined data exchange is preformed, and the application App(L) is completed, the AP 21 sends a deactivation command DEACT_COM tothe CLF 22 in Step S86. Since no protocol deactivation is performed inthe same manner as the protocol activation, the parameter “DeactivationType” of the deactivation command DEACT_COM is “NULL”.

The CLF 22 sends a deactivation response DEACT_RES representing the factthat the deactivation command DEACT_COM has been understood to the AP 21in Step S87. Thereafter, the CLF 22 deactivates the interface andreleases the parameters relating to the target 11-3 (TID3) and T3T(TSAP3).

As described above, the NFC device 1 (the AP 21 and the CLF 22) can beoperated as a polling device and detect a plurality of targets 11 withdifferent RF protocols. In addition, the NFC device 1 can sequentiallyexchange data with a plurality of detected targets 11.

[Detailed Example of Sequence (in the Case of Listen Mode)]

Next, description will be made of a sequence in which the NFC device 1is operated in the Listen Mode with reference to FIGS. 14 and 15.

In the examples of FIGS. 14 and 15, the RF protocol supported by thetarget 11-3 is NFC-DEP, unlike the example in FIG. 11.

First, the AP 21 sends an initialization command INIT_COM in Step S101,and the CLF 22 sends an initialization response INIT_RES as a responseto the AP 21 in Step S102. The initialization response INIT_RES includesan interface level for each RF protocol supported by the CLF 22 asdescribed above.

The AP 21 sends an interface level setting commandSET_INTERFACE_LEVEL_COM for associating between the RF protocol and theinterface level to the CLF 22 based on the interface level for each RFprotocol supported by the CLF 22 in Step S103. In the example of FIG.14, SET_INTERFACE_LEVEL_COM (2, Listen, ISO-DEP Protocol, Mid I/F Level,Listen, NFC-DEP Protocol, High I/F Level) is sent, and the middle levelis designated for the F protocol ISO-DEP and the high level isdesignated for NFC-DEP in the Listen Mode. Since the level of the RFprotocols T1T, T2T, and T3T are fixed to the low level, the designationthereof is omitted. In addition, each interface level in the Poll Modeis also omitted.

The CLF 22 sends an interface level setting responseSET_INTERFACE_LEVEL_RES representing that the interface level settingcommand SET_INTERFACE_LEVEL_COM from the AP 21 has been understood tothe AP 21 in Step S104.

In Step S105, the AP 21 designates NFC-A, NFC-B, and NFC-F as the RFtechnologies of the detection targets and sends a discovery startcommand DISCOVER_START_COM to the CLF 22. The CLF 22 sends a discoverystart response DISCOVER_START_RES representing that the discovery startcommand DISCOVER_START_COM has been understood to the AP 21 in StepS106.

Then, the CLF 22 firstly sends a polling command for operating the NFCdevice 1 in the Poll Mode for NFC-A, NFC-B, and NFC-F designated as theRF technologies of the detection targets. Specifically, the CLF 22sequentially sends commands SENS_REQ, SENSE_REQ, and SENSF_REQ foroperating the NFC device 1 in the Poll mode in Steps S107 to S109.

Since the responses for the commands SENS_REQ, SENSB_REQ, and SENSF_REQhave not been received, the CLF 22 then detects the polling command foroperating the NFC device 1 in the Listen Mode and responds.

Specifically, the CLF 22 receives the command SENS_REQ sent from thetarget 11-1 in Step S110 and sends the response SENS_RES to the target11-1 in Step S111.

In addition, the CLF 22 receives the command SENSB_REQ sent from thetarget 11-2 in Step S112 and sends the response SENSB_RES to the target11-2 in Step S113.

Furthermore, the CLF 22 receives the command SENSF_REQ sent from thetarget 11-3 in Step S114 and sends the response SENSF_RES to the target11-3 in Step S115.

In Step S116, the CLF 22 sends a response SRL_RES (ISO-DEP & NFC-DEP)representing that ISO-DEP and NFC-DEP are supported as the RF protocolsto the target 11-1 detected first.

Since the middle or higher interface level is designated for RFprotocols ISO-DEP and NFC-DEP of the target 11-1, the CLF 22 waits forthe protocol activation by the target 11-1. Then, the CLF 22 receives aRATS (Request for Answer To Select) for requesting for ATS from thetarget 11-1 in Step S117 and sends an ATS response for the command tothe target 11-1 in Step S118. With such operations, the protocolactivation by the RF protocol ISO-DEP is completed.

After receiving the RATS command, the CLF 22 sends an activationnotification ACT_NTF (TID1, TSAP1, NFC-A, PROTOCOL_ISO_DEP, ATS, Mid I/FLevel activated) representing that the interface activation has beencompleted to the AP 21 in Step S119.

In Step S120, the application App (M) corresponding to the middleinterface level in the AP 21 is started to exchange data between the AP21 and the target 11-1 (TID1) with the use of the RF protocol ISO-DEP(TSAP1).

After the predetermined data exchange has been performed, the CLF 22receives a command DESELECT from the target 11-1 as a PCD (readerwriter) in Step S121 and sends a DESELECT response to the target 11-1 inStep S122. With such operations, the interface with the use of the RFprotocol ISO-DEP is deactivated in the CLF 22.

Then, the CLF 22 sends a deactivation notification DEACT_NTF to the AP21 with the parameters of TID1 as “Target ID”, TSAP1 as “Target SAP”,and DESELECT as “Deactivation Parameter” in Step S123. The AP 21receives the deactivation notification DEACT_NTF and then completes theapplication App

Although data exchange is then performed with the target 11-2, which hasbeen secondly detected, for which allocation has been made such that“Target ID”=TID2 and “Target SAP”=TSAP2, the description of theprocessing will be omitted.

Then, exchange is performed with the target 11-3, which has been thirdlydetected, for which allocation has been made such that “Target ID”=TID3and “Target SAP”=TSAP3.

In Step S124 in FIG. 15, the CLF 22 receives a command ATR_REQ forrequesting the attributes from the target 11-3. The high interface levelis designated for the RF protocol NFC-DEP in the aforementioned StepS103. Therefore, the CLF 22 sends the response ATR_RES as a response tothe command ATR_REQ and performs LLCP activation in Step S125.

After the protocol activation and the LLCP activation, the CLF 22 sendsan activation notification ACT_NTF to the AP 21 in Step S126. Theparameters of the activation notification ACT_NTF include the receivedresponse “ATR_RES” as “Activation Parameter” and “High I/F Levelactivated” representing the activated interface level as “InterfaceType”.

In Step S127, the application App (H) corresponding to the highinterface level in the AP 21 is started to exchange data between the AP21 and the target 11-3 (TID3) with the use of the RF protocol NFC-DEP(TSAP3).

After the predetermined data exchange, the CLF 22 receives a commandDSL_REQ from the target 11-3 as the initiator (reader writer) in StepS128 and sends a response DSL_RES to the target 11-3 in Step S129. Withsuch operations, the interface with the use of the RF protocol NFC-DEPis deactivated in the CLF 22.

Then, the CLF 22 sends a deactivation notification DEACT_NTF to the AP21 in Step S130. Specifically, the CLF 22 sends a deactivationnotification DEACT_NTF with parameters of TID3 as “Target ID”, TSAP3 as“Target SAP”, and DSL_REQ as “Deactivation Parameter”. The AP 21receives the deactivation notification DEACT_NTF and then completes theapplication App (H).

The NFC device 1 (the AP 21 and the CLF 22) can be operated as alistening device and detects a plurality of targets 11 with different RFprotocols. In addition, the NFC device 1 can sequentially exchange datawith the detected plurality of targets 11.

The NFC device 1 for the near field wireless communication based onISO/IEC 18092 or ISO/IEC 14443 is operated while being functionallydivided into the AP 21 and the CLF 22. The AP 21 mainly executes theapplication and performs overall control of the NFC device 1. The CLF 22is disposed between the AP 21 and the target 11 and mainly sends andreceives RF data with the target 11 (a PICC (IC card) of ISO/IEC 14443or a target of ISO/IEC 18092) through the antenna 24.

The AP 21 selects (designates) one interface level from among aplurality of interface levels supported by the CLF 22 for each RFprotocol and notifies the CLF 22. The plurality of interface levels areclassified depending on up to which level of processing the CLF 22positioned in between is burdened when the NFC device 1 exchanges datawith the target 11. Specifically, when the interface level is classifiedinto three stages including a low level, a middle level, and a highlevel, the amount of the processing allotted to the CLF 22 is thelargest at the high level, and the amount of the processing allotted tothe CLF 22 is the smallest at the low level. The AP 21 obtainsinformation regarding the interface level supported by the CLF 22 anddesignates a predetermined interface level for each RF protocol withrespect to the CLF 22. Then, the AP 21 activates and executes anapplication App at a level corresponding to the designated interfacelevel. With such a configuration, the AP 21 can concentrate on theexecution of the application processing by allotting processing, whichcan be executed by the CLF 22, to the CLF 22. In addition, when the CLF22 supports a higher interface level, the CLF 22 and the AP 21 canexchange data at a higher interface level (data exchange in units inwhich the application of the AP 21 can more easily perform processing)by setting the interface level to be as high as possible. With such aconfiguration, the target 11 and the NFC DEVICE 1 can effectivelyexchange data.

When the CLF 22 is operated as a polling device, the CLF 22 sends apolling command, detects (discovers) a plurality of targets 11, and thennotifies the AP 21 of all detected targets 11 (discovery notificationDISCOVER_NTF). Then, a target 11 for communication is sequentiallyselected one by one by the AP 21 from among the plurality of detectedtargets 11, and communication (data execution by the application) isexecuted. With respect to each of the selected targets 11, operationsincluding interface activation, application execution in accordance withthe interface level (including start and completion), and interfacedeactivation are performed. With such operations, it is possible toeffectively exchange data with a plurality of targets 11 with differentRF technologies or RF protocols.

On the other hand, when the CLF 22 is operated as a listening device, atarget 11 is selected as a communication counterpart from among aplurality of targets 11, with which a communication link has beenestablished, in the detection order. The CLF 22 activates the interfacecorresponding to the RF protocol of the selected target 11 and notifiesthe AP (activation notification ACT_NTF). The AP 21 executes (includingstart and completion) the application in accordance with the interfacelevel of the target 11 for which the activation notification has beenmade. Accordingly, communication (data exchange by the application) withthe plurality of targets 11 with which a communication link has beenestablished is sequentially executed. With such a configuration, it ispossible to effectively exchange data with a plurality of targets 11with different RF technologies or RF protocols.

The above description was made of an example in which the processingnecessary for the data communication between the target 11 and the AP 21is performed by CLF 22 instead in accordance with the interface leveldesignated for a predetermined RF protocol.

However, the CLF 22 performs processing to be performed by the AP 21instead of the AP 21 in accordance with the interface level designatedfor a predetermined RF protocol in the data exchange processing betweenthe target 11 and the AP 21, in some cases.

For example, if the NFC device 1 is in a reader/writer mode, and theinterface level activated by the CLF 22 is the high level, the CLF 22performs the processing for accessing the NDEF data instead of the AP21. Here, the NDEF data is data in a common data format NDEF (NFC DataExchange Format) used by applications.

Specific description will be made of an example of an NFC FORUM Type 3Tag Operation which is a specification of Type 3 from among the TagOperations defining a command for accessing the NDEF data. When the NDEFdata is read in the NFC FORUM Type 3 Tag Operation, PollingCommand/Response and Check Command/Response are exchanged between thetarget 11 and the NFC device 1. The exchange of Check Command/Responseis performed a plurality of times in some cases in accordance with theNDEF data size. When Check Command/Response has been exchanged aplurality of times, the data obtained by coupling the data obtained byCheck Command/Response exchanged the plurality of times becomes the NDEFdata.

When the interface level of the CLF 22 is the high level, the CLF 22voluntarily executes Polling Command/Response and Check Command/Responseonce or more. When Check Command/Response is exchanged a plurality oftimes, the CLF 22 couples the data obtained by exchanging CheckCommand/Response the plurality of times to generate NDEF data. On theother hand, the interface level of the CLF 22 is the middle or lowlevel, the CLF 22 only relays Polling Command/Response supplied from theAP 21 and Check Command/Response exchanged once or more. The AP 21 alsoperforms the processing of generating the NDEF data from the dataobtained by exchanging Check Command/Response the plurality of times.

The steps described in the flowchart may of course be executed in atime-series manner in the order described in this specification, orwithout executing the steps in the time-series manner, the steps may beexecuted in parallel or at a necessary timing such as by the timing ofcalling or the like.

In addition, the system in this specification represents the entireapparatus including a plurality of apparatuses.

The embodiments of the present disclosure are not limited to theaforementioned embodiments, and various modifications can be made withinthe range of the scope of the present disclosure.

For example, a program executed to perform a method according to someembodiments need not be stored in a non-transitory storage medium. Theprogram can also be stored in a transitory storage medium, such as apropagating wave.

What is claimed is:
 1. A communication device, comprising: firstprocessing circuitry configured to detect a target and to receive afirst command upon a detection of the target; and second processingcircuitry configured to exchange data with the target through the firstprocessing circuitry, wherein the first processing circuitry is furtherconfigured to select a predetermined interface level from among aplurality of interface levels based on the first command and to exchangedata with the second processing circuitry based on the predeterminedinterface level.
 2. The communication device according to claim 1,wherein the predetermined interface level is selected based on an RFprotocol used in a communication between the target and the firstprocessing circuitry.
 3. The communication device according to claim 2,wherein the first processing circuitry is further configured to transmita second command and to receive a third command in response to thesecond command, the third command indicating the RF protocol.
 4. Thecommunication device according to claim 3, wherein the first processingcircuitry is further configured to receive from the second processingcircuitry a fourth command, the fourth command associating the RFprotocol with the predetermined interface level.
 5. The communicationdevice according to claim 3, wherein the first processing circuitry isfurther configured to send a fifth command based on the first command,the fifth command indicating the predetermined interface level.
 6. Thecommunication device according to claim 5, wherein the first processingcircuitry is further configured to start and execute an applicationbased on the predetermined interface level, the application beingconfigured to exchange data between the second processing circuitry andthe target using the RF protocol.
 7. The communication device accordingto claim 2, wherein the first processing circuitry is further configuredto receive a second command, to send a third command in response to thesecond command, and to receive the first command based on the thirdcommand.
 8. The communication device according to claim 7, wherein thefirst processing circuitry is further configured to receive from thesecond processing circuitry a fourth command, the fourth commandassociating the RF protocol with the predetermined interface level. 9.The communication device according to claim 8, wherein the firstprocessing circuitry is further configured to send a fifth command inresponse to the first command, the fifth command indicating thepredetermined interface level.
 10. The communication device according toclaim 9, wherein the first processing circuitry is further configured tostart and execute an application based on the predetermined interfacelevel, the application being configured to exchange data between thesecond processing circuitry and the target using the RF protocol. 11.The communication device according to claim 1, wherein the predeterminedinterface level is selected based on an RF technology used in acommunication between the target and the first processing circuitry. 12.The communication device according to claim 11, wherein the firstprocessing circuitry is further configured to transmit a second commandand to receive a third command in response to the second command, thethird command indicating the RF technology.
 13. The communication deviceaccording to claim 12, wherein the first processing circuitry is furtherconfigured to transmit a fourth command to the second processingcircuitry, the fourth command indicating the RF technology.
 14. Thecommunication device according to claim 13, wherein the first processingcircuitry is further configured to start and execute an applicationbased on the predetermined interface level, the application beingconfigured to exchange data between the first processing circuitry andthe target using the RF technology.
 15. The communication deviceaccording to claim 11, wherein the first processing circuitry is furtherconfigured to receive a second command, to send a third command inresponse to the second command, and to receive the first command basedon the third command.
 16. The communication device according to claim15, wherein the first processing circuitry is further configured to senda fourth command in response to the first command, the fourth commandindicating the predetermined interface level.
 17. The communicationdevice according to claim 1, wherein the first processing circuitry isfurther configured to receive a second command representing a version ofthe second processing circuitry, the first processing circuitry isfurther configured to transmit a third command in response to the secondcommand, the second command representing a version of the firstprocessing circuitry, and, when the version of the second processingcircuitry is equivalent or higher than the version of the firstprocessing circuitry, the first circuitry and the second circuitryexchange messages.
 18. The communication device according to claim 17,wherein the third command also represents the predetermined interfacelevel, and, when the version of the second processing circuitry isequivalent or higher than the version of the first processing circuitry,the second processing circuitry transmits the command, the commandindicating at least one of a poll mode and a listen mode, an RFprotocol, and an interface level.
 19. A communication method,comprising: detecting a target; receiving, at first processingcircuitry, a first message upon the detecting; exchanging data betweensecond processing circuitry and the target through the first processingcircuitry; selecting, with the first processing circuitry, apredetermined interface level from among a plurality of interface levelsbased on the first message; and exchanging data between the firstprocessing circuitry and the second processing circuitry based on thepredetermined interface level.
 20. A non-transitory, computer-readablestorage medium encoded with computer executable instructions, whereinthe instructions, when executed by a communication device, cause thecommunication device to perform a method comprising: detecting a target;receiving, at first processing circuitry, a first message upon thedetecting; exchanging data between second processing circuitry and thetarget through the first processing circuitry; selecting, with the firstprocessing circuitry, a predetermined interface level from among aplurality of interface levels based on the first message; and exchangingdata between the first processing circuitry and the second processingcircuitry based on the predetermined interface level.